Focusing objective mount



Sept' 5, 1944. c. H. HARRIS ET A1.

FOCUSING OBJECTIVE MOUNT Filed Oct. 3, 1941 John N. Graef Clinton H. Harris Mgg/yl eg Patented sees s, 1944 Clinton H. Harris and Jo Mich., Vaasiguors to Ar poration ofMichltan lm N. Graef, Ann Arbor,

, Incorporated, a oorsp'pnesnon octobers, 1941, sensi Ne. 413,516

' (ci. ntf-4s) 11 Claims.

This invention relates to focusing mounts for photographic objectives and more particularly to objective focusing mounts for-use on cameras. One of the objects of the present invention issto provide a focusing objective mount which is simple and effective in operation yet rugged and inexpensive in construction. Another object is to provide a threaded focusing mount having a smooth and uniform focusing movement throughout its range. A further object is to provide a focusing mount for photographic objectives which will maintain an objective in set position. A still further object is to provide an objective focusing mount in which a long range ofmovement is obtained while the mount is kept relatively small and compact. These and other objects and advantages reside in certain novel .features oi construction arrangement and combination of parts as will hereinafter be more fully set forth and pointed out in the appended claims.

In the drawing:

Fig. 1 is a top plan view of an objective mount embodying our invention.

Fig. 2 is a vertical section taken on line 2-2 of Fig. 1.

Fig. 3 is an exploded view of said lens mount.

Fig. 4 is la section taken on line 4 4 of Fig. 2.'

Fig. 5 is a section taken on line l--B of Fig. 2.-

A preferred form of our invention is illustrated in the drawing wherein I0 designates the body of a vcamera having illm supporting mechanism indicated generally at II. The structural details of the camera form no part of the present invention. but one suitable camera is described and claimed in U. S. patent application Serial No. 413,518, filed October 3, 1941, by Clinton H. Harris and entitled Photographic camera. The camera is provided with a front plate I2 which has an inwardly extending sleeve portion I3 threaded as indicated at Il. A sleeve Il formed with external threads I6 complemental to the threads Il of the sleeve I3 is threaded into the sleeve portion I3.' This sleeve I l also has internal threads I'I. The threads leV and I1 4are preferably of opposite hand, but may be of the same hand provided they are of diiferent pitch. In

order to give a sumcient focusing movement with a reasonable rotation of the sleeve I5, it is also preferable that the threads Il and i1 be multiple threads. A third sleeve I3 has external threads Il for engaging the threaded portion I1 of the sleeve I5. This sleeve I3 `has at itsv forward end an inwardly extending flange 20. The usual lens and shutter assembly indicated generally at 22 has a rearwardly extending threaded p0rt'ion 23 which projects through the opening in the flange 20 and is secured tothe flange 20 and sleeve I8 by a lock nut 24. A pin 2l shown in Fig. 2 extends into an aperture 2i of the 'nance zeand serves to position the lens and shutter assembly 22 relative to the sleeve I3- A key member 23 within the smooth bore of the sleeve I8 is formed with tongues 2l which bear frictionally against this inner bore. The key 2t is free to slide longitudinally within the sleeve I! but is held against rotation by thel inwardly extending pins-or studs 23 which are ixed in the sleevev Il -and extend into longitudinal slots 2e in the key member 2|. These slots 23 are formed in a pair of fingers 3l which extend rearwardly from thekey member 20 and terminate in outward nanges 3 I.

A pair of -pIns or studs 32 are fastened to and extend outwardly 'from the anges'3l into a pair of longitudinal grooves 33 formed in the threaded portion I4 of the sleeve I3. Thus, it can be seen that the sleeve Il is held by means oi' the key 26 against rotation relative to the sleeve I3 so that rotation of the intermediate sleeve I5 will cause an axial movement of the lens and shutter assembly 22. The flanges 3| serve to limit the extent of this focusing mech- ,anism by abutting the sleeve Il in one direction of movement and the film holding mechanism II in 'the other direction of movement, The use of a traveling key. that is, a key which. has a sliding connection to both the sleeve I3 and the sleeve I3 permitsan unusually long move-v ment while the overall depth of the mount is not unduly increased.

A collar 34 provided with a lcnurled ring 35 is secured to the sleeve -I5 by a plurality of set screws 36. This collar forms aconvenient means fox-.rotating the focusing sleeve I5 and it is preferably graduated as indicated at 3l in Fig. 1.

The key 26 is preferably formed of a springy material and the fingers 30 bear lightly outward to press the pins 32 into the grooves 33. I'he 40 tongues 21 also bear frictionally against the inner wall of the sleeve I8, thus affording a smooth frictional focusing movement and securely holding the lens against accidentalmovement after it has been brought into proper position.

From the foregoing, it will be apparent that we are able to attain the objects of our invention and provide a simple and inexpensive focusing objective mount which has a smooth and uniform movement throughout its range and in which the lens is held against accidental displacement. While we have illustrated our invention as applied to a particular type or camera, it is apparent that it may be applied to cameras of many different types, or may be applied to a focusing lens mount separate from a camera.

Having thus described our invention, what we Patent, is:

1. In a focusing mount foriobiectives in combination, a support, an inner sleeve axially slidably mounted in said support, an objective lens 2. A focusing mount for objectives comprising a support having an internally threaded bore, an annular'sleeve threaded in said bore, the interior of said annular sleeve being also threaded, an inner sleeve threaded in the interior of said annular sleeve, an objective carried by said inner sleeve, a traveling key member frictionally engaging the interior of said inner sleeve, means for preventing relative rotation between said inner sleeve and said key member, a pair of diametrlcally opposite projections extending rearwardly from said key member and interengaging means on said projections and on said support for -preventing relative rotation between said projections and said support.

3. A focusing mount for objectives comprising an outer fixed sleeve, an intermediate sleeve threadedly connected thereto, an inner sleeve threadedly connected to said intermediate sleeve, means for mounting an objective on said inner sleeve, an axially slidable key member, means for slidably connecting said key member to said inner sleeve and means for slidably connecting said key member to said xed sleeve.

4. A focusing objective mount comprising a iixed sleeve, a focusing sleeve threadedly mounted said lens sleeve against rotation so that said lens sleeve has only axial sliding movementwhen said focusing sleeve is rotated, said axially traveling means comprising a frictionally mounted key slidable axially of said sleeves and having parallel pin and slot connections with said iixed* sleeve and said lens sleeve.

'1. Ina camera, a ilxed 'support, a rotatable focusing member on said support, a lens tube threadedly mounted within said sleeve, an axially displaceable key member-frictionally mounted on said tube, a pin and groove connection between said key member and said lens tube permitting relative axial displacement thereof but holding said key member and lens tube against relative rotation, and a second pin and groove connection between said key member and said fixed support permitting relative axial displacement but holding the key member against rotation, saidgrooves being substantially parallel to the lens axis so that rotation of said focusing member produces only axial displacement of said lens tube.

8. In a camera having a body providing a forwardly facing recess, an objective mount coopwithin said ilxed sleeve, a lens sleeve threadedly 'mounted within said focusing sleeve, means for mounting an objective on said lens sleeve, a traveling key axially slidably mounted within said lens sleeve, cooperating means on said lens sleeve and traveling key'iorming a longitudinally sliding connection between said key and lens sleeve, cooperating means on said iixed sleeve and said key forming a longitudinally sliding connection between said key and said xed sleeve, and frictional holding means between said key and said lens sleeve.

5. A focusing objective mount for cameras comprising a support, an objective mount longitudinally movable within said support, right and left hand threads Von the mount and support, an adjusting sleeve connecting the mount and support and having right and left hand threads engaging the threads on the mount and support, an axially slidable annular ring within said mount in frictional engagement with the wall of said mount, longitudinal guide means on said ring, means on said mount operatively engagingv said guide means, and means operatively connecting v said support and said ring for preventing rotainterior of said lens sleeve.

erating with said Irecess, comprising a lens sleeve; 'means mounting said lens sleeve for axial movement from a collapsed inoperative position with respect to said recess to an extended operative position with respect to said recess, and also being axially movable from the latter position outwardly to a near focus position; and means cooper. ating with said camera body and said lens sleeve for restraining said lens sleeve against rotation while permitting'free axial movement thereof, comprising a guiding device having keying engagement with both said camera body and said lens sleeve and operable to undergo a total axial movement with respect to said body and sleeve which is materially less than the total axial travel of said lens sleeve from said collapsed position to said near focus position.

9. Theycamera construction defined in claim 8, wherein said means for mounting said lens sleeve comprises an intermediate sleeve disposed between and threadedly connected -to said lens sleeve and the wall of said recess, and the rear end of said intermediate sleeve is operable to contact a portion of said guiding device and limit travel of the latter in one direction of movement of said lens sleeve.

10. The camera construction dened in claim 8, wherein said camera body is provided with a forwardly facing wall adjacent the bottom o f said recess operable to contact a portion of said keying device and limit rearward travel of said keying device in response to movement of said lens sleeve toward collapsed position. v

11.-.'1he camera construction dened in claim 8, wherein said means for mounting said lens'sleeve comprises. an intermediate sleeve disposed between and I. threadedly connected to said lens sleeve andthe wall of said recess, and said guiding device comprises a guide member axially slidable in said lens sleeve and having a plurality of keys projecting outwardly beyond said intermediate sleeve and seating in parallel keyways provided in said wall of said recess, said guide member having a plurality of keyways paralleling the keyways of said recess and cooperating with a plurality of keys provided on the CLINTON H. HARRIS; J. N. GRAEF. 

